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im not a pro., but if u dont understand the purge , what it does and how it works, let me suggest more reading., but to try to answer ur question,

like u said , exhaust solenoid, solenoid is electrical the valve has a seal.,
if seal is compromised , yes i am assuming that air will be pulling in and hopefully pulled back out with the purge.,

., if there is excessive purge, time to find leak.,
isolate chiller.,
adjust water lever in chiller., create a positive pressure.,
tighten all flat gaskets., and if still excessive purge., well , lets see if the true pros add in.,.,

MY QUESTION IS when does someone know it is time to change exhaust valve?

What keeps the purge from sucking back through the exhaust solenoid during the regeneration cycle?

Well.....the exhaust solonoid itself will keep air from sucking through itself during regeneration because its deenergized. Unless the valve is bad and leaking.

Originally Posted by mlkwal1

im not a pro., but if u dont understand the purge , what it does and how it works, let me suggest more reading., but to try to answer ur question,

like u said , exhaust solenoid, solenoid is electrical the valve has a seal.,
if seal is compromised , yes i am assuming that air will be pulling in and hopefully pulled back out with the purge.,

., if there is excessive purge, time to find leak.,
isolate chiller.,
adjust water lever in chiller., create a positive pressure.,
tighten all flat gaskets., and if still excessive purge., well , lets see if the true pros add in.,.,

MY QUESTION IS when does someone know it is time to change exhaust valve?

I would suggest isolating the purge and doing a complete checkout of the purge before searching for a leak in the chiller.

When the purge is in a regeneration cycle, the exhaust solenoid is closed. The regeneration solenoid is open and the heater energizes to drive the refrigerant out of the carbon tank and into the evaporator.

thanks guys., always check purge first huh?
would this be considered one of those ozzey area that need to be checked ., kinda like the eonomizer gaskets?

and there u go Luke.,
keep us posted.,

The purge is the lowest common denominator. It's a whole lot cheaper and easier to fix than pressurizing the chiller and leak testing. There's a short list of things that I always check on every one before I go and pressurize the machine for a leak test.

It's all in the name of efficiency. I am not 100% convinced of the effectiveness of the earthwise design, though. The new carbon tank and extra solenoid seem to create more problems than anything

I was alluding to the industry concerns regarding the future availability of R-123. I know increasing the efficiency of the purge for sake of "reducing emissions" is a legitimate reason for the purge design change but... I find it interesting that Trane attempts to dis-spell these R-123 shortage myths and then adds this provision to their purge to mitigate ref. loss. Just seems a little suspicious to me because the previous purge design was actually very efficient to begin with. Unless you had a "hole" in your chiller and/or you by-passed the restrictor tee and pumped out for a week, refrigerant loss was nil.

The purge is the lowest common denominator. It's a whole lot cheaper and easier to fix than pressurizing the chiller and leak testing. There's a short list of things that I always check on every one before I go and pressurize the machine for a leak test.

I agree with you Rob... Next to the economizer gaskets, the biggest source of leaks is (ironically) the place where the non-condensables are supposed to be removed.

Just want to say... NOT PICKING ON TRANE, read: you Trane guys... I worked for Trane and I DO think they make a good machine... It will just be interesting to see how things unfold here in the states in the coming years...

Well, everyone thought that once R-11 production stopped, you wouldn't be able to get it at a reasonable price. No manufacturer has made an R-11 chiller in 20 years, and supplies are still plentiful. You can practically walk into Wally-World and buy it off the shelf. I suspect the same will be true for R-123. There are not many small low pressure centrifugal chillers being installed anymore. The older chillers in the 250-500 ton range are slowly being replaced by disposable scroll and screw chillers. We are still starting up lots of new ones in the 1000 to 3000 ton range though because the efficiency of a direct drive, hermetic, low pressure design makes sense for big district plants.